Annealed AISI 440A vs. Annealed AISI 440B
Both annealed AISI 440A and annealed AISI 440B are iron alloys. Both are furnished in the annealed condition. Their average alloy composition is basically identical.
For each property being compared, the top bar is annealed AISI 440A and the bottom bar is annealed AISI 440B.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 20 | |
| 18 |
| Fatigue Strength, MPa | 270 | |
| 260 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 77 | |
| 77 |
| Shear Strength, MPa | 450 | |
| 460 |
| Tensile Strength: Ultimate (UTS), MPa | 730 | |
| 740 |
| Tensile Strength: Yield (Proof), MPa | 420 | |
| 430 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 280 |
| Maximum Temperature: Corrosion, °C | 400 | |
| 390 |
| Maximum Temperature: Mechanical, °C | 760 | |
| 870 |
| Melting Completion (Liquidus), °C | 1480 | |
| 1480 |
| Melting Onset (Solidus), °C | 1370 | |
| 1370 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 23 | |
| 23 |
| Thermal Expansion, µm/m-K | 10 | |
| 10 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.5 | |
| 2.5 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.9 | |
| 2.9 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.0 | |
| 9.0 |
| Density, g/cm3 | 7.7 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 2.2 | |
| 2.2 |
| Embodied Energy, MJ/kg | 31 | |
| 31 |
| Embodied Water, L/kg | 120 | |
| 120 |
Common Calculations
| PREN (Pitting Resistance) | 18 | |
| 18 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 110 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 440 | |
| 460 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 26 | |
| 27 |
| Strength to Weight: Bending, points | 23 | |
| 24 |
| Thermal Diffusivity, mm2/s | 6.2 | |
| 6.1 |
| Thermal Shock Resistance, points | 26 | |
| 27 |
Alloy Composition
| Carbon (C), % | 0.6 to 0.75 | |
| 0.75 to 1.0 |
| Chromium (Cr), % | 16 to 18 | |
| 16 to 18 |
| Iron (Fe), % | 78.4 to 83.4 | |
| 78.2 to 83.3 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0 to 0.75 | |
| 0 to 0.75 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.015 |